Zinc alloy containing nitrogen

ABSTRACT

A zinc base alloy which can be used for mechanically loaded structural components, contains iron, lead, copper, cadmium, and particularly nitrogen.

United States Patent [191 Balevski et al.

[ Nov. 26, 19741 ZINC ALLOY CONTAINING NITROGEN Inventors: Anguel Tonchev Balevski; Ivan Dimov Nikolov; Vasilka Petrova Dimova; Stoyan Nedkov Zadgorski, all of Sofia, Bulgaria Institute Po Metaloznanie I Techno Logia Na Metalite, Sofia, Bulgaria Filed: Oct. 16, 1973 Appl. No.: 406,848

Assignee:

Foreign Application Priority Data Oct. 16. 1972 Bulgaria 21636 US. Cl 75/178 R, 75/178 D, 75/178 CL,

75/178 C Int. Cl. C22c 17/00 Field of Search 75/178 CL, 178 D, 178 C, 75/178 R Primary Examiner-L. Dewayne Rutledge Assistant Examiner-E. L. Weise Attorney, Agent, or Firm-Karl F. Ross; Herbert Dubno [5 7] ABSTRACT A zinc base alloy which can be used for mechanically loaded structural components, contains iron, lead, copper, cadmium, and particularly nitrogen.

1 Claim, 2 Drawing Figures w @I N @I ow on ow QM om m v6 m6 N6 5Q PATENTEL MIN 26 I974 ZINC ALLOY CONTAINING NITROGEN This invention relates to a zinc alloy, particularly an alloy of high and stable mechanical properties, which can be used after plastic forming as a material -for loaded structural components.

Commercially pure zinc and its alloys are used on a very limited scale for galvanizing, in the production-of galvanicelements, in typography and in other cases where no corrosion resistance and strength properties are required. However, these alloys cannot be used for mechanically loaded components because of their low mechanical strength, as well as their low recrystallization temperature. For example, a zinc alloy containing 0.3 percent iron has a temperature of beginning of recrystallization of 30C and a tensile strength of 14.5 kgf/mm after press-working at 100C and a degree of deformation of e 80 percent. This temperature is in the range of normal room or atmosphere temperature, which means that at this temperature the material begins to creep, the crystals begin to transform themselves and with the time a deformation of the continuously (permanently) loaded components takes place.

It is therefore a general object of the present invention to provide for an increase and a stabilization of the strength properties of zinc, i.e., to obtain an alloy of higher strength, featuring a sufficiently high temperature of beginning of recrystallization.

The zinc alloy containing iron, lead, copper and cadmium, contains according to the present invention also nitrogen. This zinc alloy has the following composition (all percentages are by weight):

iron 0.05 0.57: nitrogen 0.0005 0.5% lead less than 0.015% copper less than 0.007% cadmium less than 0.015%

nitrogen and carrying out the solidification at a considerably higher partial pressure of the nitrogen in the gas atmosphere than the pressure at which it has been saturated.

EXAMPLE A zinc alloy according to the invention containing 0.3 percent iron, 0.015 percent cadmium, 0.007 percent copper, 0.0l5 percent lead and 0.0006 percent nitrogen, which after plastic forming at a degree of deformation F percent features a tensile strength of 0,, 23.4 kgflmm This alloy has a considerably higher strength and recrystallization temperature than all hitherto known zinc alloys. If no nitrogen is contained in this same alloy, its strength is only 14.5 kgflmm The diagram in FIG. 1 shows the dependence of the temperature of beginning of recrystallization of the zinc alloy on the iron content. Curve 1 shows the temperature of beginning of recrystallization of the zinc alloy without nitrogen, while curve 2 is valid for a nitrogen content according to the example. The degree of deformetion is F 50 percent and the duration. of annealing is 2 hours. At aniron content of 0.3 percent the temperature of beginning of recrystallization is r 170C. This is a sufficiently high temperature, and it can be assumed that this alloy can be used in all normal cases for general engineering components. After natural ageing the high strength of the zinc alloy containing nitrogen is preserved.

The diagram in FIG. 2 shows the dependence of the tensile strength on the degree of deformation in plastic forming (press-working at C) of the alloy according to the example. i v

The corrosion resistance of the disclosed zinc alloy remains the same as in the case of pure zinc.

What we claim is:

l. zinc base alloy, consisting essentially of (all percentages are by weight):

iron 0.05 0.5% nitrogen 0.0005 0.571 lead an effective amount up to 0.015% copper an effective-amount up to 0.0079: cadmium an effective amount up to 0.015% zinc the remainder 

1. A ZINC BASE ALLOU, CONSISTING ESSENTIALLY OF (AL PERCENTAGES ARE BY WEIGHT): 